1. Field
The present invention relates generally to antennas and, in particular, to structurally integrated antennas. More particularly, the present disclosure relates to a method and apparatus for a slot antenna that is a composite structure or is integrated into a composite structure.
2. Background
Antennas are used in many applications to transmit and/or receive radio frequency signals. Antennas are commonly used on aircraft. For example, an antenna on an aircraft may be used to provide communication between the aircraft and another aircraft, a ground station, a satellite, and/or some suitable type of platform.
Antennas can also be used in radar systems on aircraft. When used in a radar system, antennas may aid in detecting objects, such as, for example, ground objects, maritime objects, airborne objects, and/or other suitable types of objects. Antennas used in radar systems may also support generating images, such as synthetic aperture radar images, inverse synthetic aperture radar images, and/or other suitable types of radar images. In this manner, antennas may be used in communications and remote sensing.
Different parameters are taken into account in designing antennas for aircraft. These parameters may include a desired level of performance for remote sensing and communications functions. Further, the antennas may be required to take into account the constraints of the aircraft for which these functions are performed.
Weight, size, and shape of antennas are additional examples of parameters taken into account in antenna design for aircraft. Reducing the weight of an aircraft by reducing the weight of an antenna may increase the fuel efficiency or the distance an aircraft may travel. Further, the size of the antenna may place constraints on what other components may be included in the aircraft and may place constraints on the design of the aircraft. Reducing the size of the antenna may reduce space issues in an aircraft. Also, the shape of the antenna on the aircraft may affect performance of the aircraft. For example, depending on the shape of the antenna and a required orientation for the antenna, undesired drag on the aircraft may be introduced.
With respect to unmanned aerial vehicles, ultrahigh frequency (UHF) radar systems may be mounted in pods attached to unmanned aerial vehicles (UAVs). Currently designed antennas for these radar systems may have undesired characteristics.
For example, depending on the specific implementation, pods containing antennas may be as long as about 21 feet long. The weight of these pods may reduce the time or distance that an unmanned aerial vehicle can fly. These reductions may increase as the size of the unmanned aerial vehicle decreases. Therefore, it would be advantageous to have a method and apparatus that takes into account at least some of the issues discussed above, as well as other possible issues.